For 50 years, since Dave Keeling started monitoring carbon dioxide at Mauna Loa, Hawaii, and the South Pole, scientists have been tracking greenhouse and other trace gases in the global atmosphere. The results have revolutionized our understanding of biogeochemistry and demonstrated that human activities affect climate change and air quality.

Dramatic and sustained improvements have occurred in our prediction capabilities for air quality, climate and weather. Nevertheless, the demands for more accurate predictions have increased due to the exponential growth of population, climate change and the increasing susceptibility of society to natural disasters and poor air quality by concentrating populations in urban centres, coastal regions and river valleys.